Ryder



E. RYDER Aug. 18, 1959 VARIABLE DISPLACEMENT PUMP 2 Sheets-Sheet 1 Filed Dec. 7. 1956 m m m m ELMER RYDEIL E5) WW K%TTORNEY6 United States Patent VARIABLE DISPLACEMENT PUMP Elmer Ryder, Aurora, Ill.

Application December 7, 1956, Serial No. 627,000

3 Claims. (Cl. 103-120) This invention relates to improvements in sliding vane rotary pumps and more particularly relates to such pumps in which the displacement of the pump may be varied.

A principal object of the invention is to provide an improved form of variable displacement pump in which the displacement of the pump is varied' at the selection of the operator in a simpler manner than formerly.

Another object of the invention is to provide an improved form of variable displacement pump in which the displacement of fluid impelled through the outlet is varied by feeding back a certain proportion of the fluid and by varying the proportion of the fluid fed back.

A still further object of the invention is to provide a variable displacement sliding vane type of pump having an inlet and an outlet, in which a feed-back port is positionable between the inlet and the outlet to feed back a certain proportion of the fluid being pumped, and in which the position of the feed back port is adjustable at the will of the operator of the pump, to control the proportion of the fluid by-passed past the outlet for the pump.

A further object of the invention is to provide a more eflicient sliding vane pump in which oil pockets between the vanes are eliminated and in which the vanes are so arranged as to reduce the friction occasioned by reciprocable movement thereof.

A still further object of the invention is to provide a novel and improved form of sliding vane pump having a I rotor having sliding vanes reciprocably carried therein, in which the friction of sliding movement of the vanes is reduced by providing two vanes in side by side relation with respect to each other extending diametrically of the rotor, and providing an engaging area between the vanes so as to reduce the frictional resistance to reciprocable movement thereof.

These and other objects of the invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

Figure 1 is an end view. taken through a variable displacement pump constructed in accordance with the invention;

Figure 2 is a sectional view taken through the pump shown in Figure 1 substantially along line II--1I of Figure 3; and

Figure 3 is a transverse sectional view taken through pump substantially along line IIIIII of Figure 1.

In the embodiment of the invention illustrated in drawings, I have shown a pump 10 having a rotor 11 rotatably mounted within a pumping chamber 12, the wall of which is generally cylindrical in form and is eccentric of the axis of rotation of said rotor. The chamber 12 is formed internally of a pumphousing 13, having an inlet 15 leading into said housing and an outlet 16 leading from the pumping chamber 12 and from said housing in angularly spaced relation with respect to the inlet 15.

The pump housing 13 has a flange 17 extending thereabout having an end plate 19 secured thereto as by nuts and bolts 20. Suitable sealing means (not shown) may ice be provided between the flange 17 and the end plate 19 to seal the housing against the leakage of fluid. The housing 13 also has a hollow boss 21 extending therefrom concentric with the center of the rotor 11, and eccentric of the center of the chamber 12. and having a bearing 18 for a rotor shaft 22 suitably mounted therein. The rotor shaft 22 is shown as having a disk 23 on its inner end, suitably secured to one end of. the rotor 11 as by machine screws 24. The shaft 22 may form a drive shaft for the pump and may be driven by a suitable motor (not shown). I g V The end plate 19 has a hollow boss 25 formed integrally therewith, concentric with the center of the hollow boss 21 and pump drive shaft 22. The hollow boss 25 has a hub 26 of an end plate 27 for the chamber 12 mounted therein for angular movement with respect thereto. The end plate 27 abuts the outer face of the flange 17 and is rotatably carried within a recessed portion 29 of the end plate 19 for angular adjustment with respect thereto.

The end plate 27 extends along the opposite end of the rotor 11 from the disk 23 and shaft 22 and has a disk 30 recessed therein. The disk 30 is shown as being secured to the opposite end of the rotor 11 from the disk 23 as by machine screws 31 and as having a shaft 33 extending outwardly therefrom and journalled within .the hub 26 of the end plate 27 on a bearing 34.

The rotor 11 is shown as having a slot 35 extending diametrically thereacross and to each side of the center thereof. The slot 35 slidably carries two sliding vanes 36 and 37, slidably mounted in said slot in side bysid'e relation with respect to each other, Each vane 36 and 37 is longer than the slot 35 and extends beyond the periphery of the rotor 11 for engagement with the cylindrical wall of the chamber 12. The rotors 36 and 37 are each shown as having slotted central portions 39 and 40, respectively, receiving a compression spring 41 having one end 43 extending within an end wall 44 of the slot 39 and having an opposite end 45 extending .within an end wall 46 of the slot 40, and facing the end wall 44. The spring 41 thus biases the vanes 36 and 37 apart .and yieldably engages said vanes with the wall of the chamber 12, to slide along said wall, upon rotatable movement of the motor 11, and impel fluid from the intake 15 to the outlet 16 in a manner usual with sliding vane types of pumps.

It should here be noted that the sliding vanes 36 and 37 have slidable engagement with the opposite walls of the slot 35 for substantially the entire length of said slot.

The opposite walls of the slot thus form a relatively. long bearing area for the vanes, maintaining said vanes in aligned relation with respect to each other and reducing any tendency for said vanes to tilt in their slots, and thus reducing the friction occasioned by reciprocable movement of the vanes, over the friction of vanes on the usual forms of sliding vane pumps, in which the two vanes are in aligned relation with respect to each other and have slidable bearing engagement with the rotor slot for substantially half the length of the slot.

The construction shown and described also eliminates any pockets at the inner ends of the vanes of' the rotor, which may collect oil therein and thereby increase the resistance to inward movement of the vanes as they slide along the wall of the pumping chamber. The slotted central portions of the vanes are always of the same volumetric capacity and thereby entirely eliminate'the problem of oil collecting in the pockets heretofore present between the adjacent ends of the vanes and restricting reciprocable movement of the vanes with respect to each other. 1 1.

Referring now in particular to the means for varying ,the displacement, of the pump, the plate 27 has a feed may be connected back to the intake '15, to feed back a certain proportion of the fluid in accordance with the jposition of the port 47 with respect to the outlet 16 from the'p'ump, and thus vary the displacement of the pump in accordance with the proportion of fluid fed back "through the port '47.

-A lever 53 is provided to angularly move the plate27 i 'with respect to the pumping chamber 12 and to vary the "'position'of the port 47 with respect to the inlet 15 and the outlet 16. The lever 53 is shown as being keyed to the end of the hub 26 f the plate 27 and as extending along and beyond the-end of the boss 25. The lever 53 "may be connected with an index lever (not shown),

which may be pivoted to pivotally move the lever within the boss 25, and may be held in position to hold the lever 53, plate 27 and port 47 in a desired position 'withlrespect to the inlet 15 and outlet 16 from the pump. The means for operating the lever 53 and holding it in "position forms no part of the present invention and may be of various well known forms, so need not herein be shown or described further.

It will be apparent from the foregoing that when the port 47 is positioned adjacent the inlet 15, that a minimum amount of fluid will be fed back to tank or to the intake for the pump, if the outlet 50 is connected to the intake,

and that in this position, the volume of fluid displaced through the outlet 16 will be the greatest. As, however, 'the plate 27 is angularly moved toward the outlet 16 with a corresponding movement of the port 47, the displacement of the pump will be decreased and when theport 47 is in registry with the outlet 16, all of the flui'd will be fed back to tank or to the intake dependingupon where'the outlet 50 from the passageway 49 is connected. The outlet 16 is connected with an outlet fitting 55 having a check valve 56 therein, herein shown "as being a usual form of ball type check valve, to retain the fluid from flowing back to the pumping chamber.

' It should here be understood that the speed of rota- -tion of the rotor 11 is constant and that the displacement is varied by varying the amount of fluid fed back to the tank or to the intake, with the result that an extremely simple variable displacement pump has been provided in which an infinite number of variations in the volumetric displacement of the pump may be attained, which is particularly suitable for operating hydraulic devices such .as lifts, digger buckets and the like, to provide the desired feel in digging or lifting and vary the digging or lifting force at the will of the operator.

It should be understood, however, that the pump of my invention is adapted for various uses and is particularly suitable for operating drill presses and like .machine tools, where variable displacement and feed is required or desirable.

Well I have herein described one form in which {my invention may be embodied, it will be understood that various modifications and variations of the invention may be effected without departing from the Eispirit and scope of the novel concepts thereof.

I claim as my invention: 1. ha variable displacement rotary pump, a housing, a chamber within said housing having a cylindrical Wall ;and spaced facing end walls, 'a rotor within said chamber :eccentric of the'ce nter of said chamber, the space between the periphery of said rotor and said cylindrical wall defining a crescent shaped pumping chamber, said rotor having in slot extending diametrically thereacross," at least one sliding vane slidably mounted in said slot and having slidable engagement with said cylindrical wall, an inlet into said pumping chamber at one end thereof, an outlet from said pumping chamber at the opposite end thereof, a semicircular passageway in an end wall of said chamber, extending fro-m a position adjacent said inlet to a position adjacent said outlet, an'ou'tletfrom said passageway adjacent said outlet from said chamber, .a plate rotatably mounted in said chamber and coverin'g'said semicircular passageway, a port leading through said plate in communication with said semicircular passageway, and means for rotatably moving said plate and varying the position of said port between said inlet and said outlet and thereby varying the quantity of fluid displaced through said outlet from said semicircular passageway and the quantity of fluid displaced through said outlet from said pump.

2. In a variable displacement rotary pump, a housing, a chamber in said housing having a'cylindrical wall and oppositely facing end walls, a rotor rotatably mounted within said chamber eccentric of the center of said cylindrical wall and with said cylindrical Wall defining a crescent shaped pumping chamber, said rotor having a slot extending diametrically thereacross, a pair of diametrically opposed sliding vanes slidably mounted in said slot and having slidable engagement with each other, spring means connected between said vanes and biasing said vanes outwardly of the periphery of said rotor into engagement with said cylindrical wall, an inlet at one end of said pumping chamber, an outlet from the other endof said pumping chamber, a semicircular passageway in one end wall of said chamber extending from a position adjacent said inlet to a position adjacent said outlet, a plate rotatably mounted in said chamber concentric with the center of said wall, a port leading through said plate and having communication with said semicircular passageway, an outlet from said semicircular passageway leading from the end thereof adjacent said outlet from said pumping chamber, and means for adjustably moving said plate and varying the position of said portleading therethrough between said inlet into said pumping chamber and said outlet leading therefrom and thereby varying the quantity of fluid bypassed through said outlet leading from i said semicircular chamber and the quantityof fluid bypassed through said outlet from said pumping chamber.

journalling said rotor in said chamber for rotation about an axis coaxial with the axis ofsaid rotor and eccentric of the center of said cylindrical wall, the periphery of said rotor with said cylindrical wall defining a generally crescent shaped pumping chamber, said rotor having a diametrically extending slot therein, a pair of diametrically opposed sliding vanes slidably mounted in said slot and having slidable engagement with each other, spring means connected between said vanes and biasing said vanes outwardly of the periphery of said rotor into engagement with the wall of said chamber, an inlet leading into said pumping chamber adjacent one end thereof, an outlet leading from said pumping chamber adjacent the opposite end thereof, a generally circular passageway in one end wall of said chamber extending from a position adjacent said inlet to a position adjacent said outlet, a plate rotatably mounted within said chamber'for rotation about an axis coaxial with the center of said chamber and covering said semicircular passageway, an

outlet from said semicircular passageway leading from the end thereof adjacent said outlet from said pumping chamber for by-passing fluid to a low pressure area, a port leading through said plate in communication'with said semicircular passageway and :movable along .said semicircular passageway from one .end'thereof to the other to vary the quantity "of fluid displaced through Iisaid 5 outlet leading from said semicircular passageway, and 1,434,716 means for angularly adjusting said plate and varying the 1,482,807 position of said port along said semicircular passageway 1,486,835 and thereby varying the capacity of said pump from zero 2,037,894 to maximum capacity. 2,302,411 2,509,321 References Cited in the file of this patent 2 5 5 077 UNITED STATES PATENTS 2,565, Re. 23,086 H011 Feb. 22, 1949 gggg'gg 232,901 Phillips Oct. 5, 1880 2728'297 723,656 Dunn Mar. 24, 1903 2749843 884,747 MacNish Apr. 14, 1908 940,056 Pocock Nov. 16, 1909 953,539 Mendizabal Mar. 29, 1910 1,283,089 Connor Oct. 29, 1918 15 113,694

6 Marion Nov. 7, 1922 Newberg Feb. 5, 1924 Hill Mar. 11, 1924 Grisell Apr. 21, 1936 Behrens NOV. 17, 1942 Topanelian May 30, 1950 H011 Aug. 21, 1951 Lester Aug. 28, 1951 Holl Oct. 2, 1951 Berg Mar. 3, 1953 Cilley Dec. 27, 1955 'Nubling June 12, 1956 FOREIGN PATENTS Australia Aug. 15, 1941 

